Evaluation of liver test abnormalities in a patient-centered medical home: do liver test patterns matter?

Abnormal liver tests are extremely common in clinical practice, present with varying patterns and degrees of elevation, and can signal liver injury from a variety of causes. Responding to these abnormalities requires complex medical decision-making and merits investigation in primary care. This retrospective study investigates the association of patterns of liver test abnormality with follow-up in primary care. Using administrative data, this study includes patients with abnormal liver tests seen between 2007 and 2016 in a patient-centered medical home. Liver tests examined include serum bilirubin, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase. Patients entered the cohort on the first liver test elevation. The outcome examined was completion of repeat testing, and the proportions of patients without follow-up were compared by patterns of index abnormality. 9545 patients met the inclusion criteria. Of these, 6155 (64.5%) possessed one liver test abnormality and 3390 (35.5%) possessed multiple abnormalities on index testing. Overall 1119 (11.7%) patients did not have repeat testing performed during the study period. A greater proportion of patients with lone abnormalities lacked repeat testing compared with those patients with multiple abnormalities. Differences in repeat testing appeared when comparing clinical patterns of abnormality, with higher proportions of follow-up in patients with testing suggestive of cholestasis. Over 11% of patients with abnormal liver tests did not undergo repeat testing during the study period. Repeat testing occurred more often in patients with multiple abnormalities and in clinical patterns suggestive of cholestasis. This study highlights a potential opportunity to improve quality of care.